Insert value if value does not exist in another table

Question

I would like to check if all values in column releases.id exist in column charts_extended.release_id

If the value does not exist then I want to insert that value in column releases.id into column charts_extended.release_id

Please show your table and columns and also the query you've tried to work on too. — Makudex, Sep 08 '15 at 10:23
please see this link: http://stackoverflow.com/questions/1361340/how-to-insert-if-not-exists-in-mysql — Makudex, Sep 08 '15 at 10:24

score 1 · Accepted Answer · answered Sep 08 '15 at 10:23

You should first come up with query to check whether the id exists in the table, for example:

SELECT id 
FROM releases
 LEFT JOIN charts_extended ON (release_id=releases.id)
WHERE release_id IS NULL;

If you are happy with that, you can proceed into converting it to an INSERT statement:

INSERT INTO charts_extended (release_id) 
SELECT id 
FROM releases
 LEFT JOIN charts_extended ON (release_id=releases.id)
WHERE release_id IS NULL;

1 Answers1